Hi!

Here's a bug with advices.
Test case :
$ emacs -Q
M-: (defadvice forward-line (before foo activate))
M-x describe-function RET forward-line RET prints:
|
| This subr is advised.
|
| Before-advice `foo'.
`--------------------------

Now, use M-x ad-remove-advice RET RET RET RET (the default each time)
There's two annoying things :
1. M-x describe-function RET forward-line RET says :
| This subr is advised.
`--------------------------

although there's no more advice,

2. M-x ad-remove-advice default values are impossible.

I propose this (maybe too heavy, only parts may suffice) change: